Recipe A makes 5 dinner rolls using 1 c of flour. Recipe C makes 45 rolls using 10 c of flour. Which recipe requires the most flour per roll?

Okay. Basically, what we have to do here is is the amount of flour per roll, which requires dividing cups of flour by the number of rolls. 1/5 is 0.2 or 1/5 in simplest form. Recipe A uses 1/5 cup of flour per roll. 10/45 is 0.2222 and an infinite number of 2's behind it or 0.22 when rounded to the nearest hundredth. Recipe C uses about 0.22 cups of flour per roll. 0.22 > 0.2, so recipe C uses the most flour per roll.